Crosslinked Resist Underlayer Composition for Fine Pattern Transfer

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Solution Overview

Problem

Conventional resist underlayer films face challenges with low dry etching resistance, pattern collapse due to high aspect ratios, and inadequate etching selectivity between the photoresist film and substrate, especially in fine patterning processes for semiconductor devices.

Innovation Solution

A composition for forming a resist underlayer film comprising a polymer with specific structural formulas and a crosslinking agent, along with optional additives, which enhances etching resistance and thermal flowability, allowing for improved filling and planarizing properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a photoresist film is thinned to improve resolution for fine patterning, then resolution performance is improved, but etching resistance is reduced

Engineering Contradiction:
Improveresolution performanceVSAvoidetching resistance
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The patent divides the resist system into two separate layers: a photoresist film for pattern formation and a resist underlayer film for etching resistance. This segmentation allows each layer to be optimized independently - the photoresist film can be thin for high resolution while the underlayer provides the necessary etching protection during substrate processing

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The resist underlayer film acts as an intermediary between the photoresist film and the substrate. It receives the transferred pattern from the photoresist and protects the substrate during etching, mediating the interaction between the pattern-forming layer and the substrate to enable fine patterning with maintained etching resistance

Inventive Principle:
Principle #24Intermediary (Mediator)

2Length of moving object

If a pattern width is reduced without changing photoresist film thickness, then miniaturization is achieved, but resolution performance is lowered

Engineering Contradiction:
Improvepattern widthVSAvoidresolution performance
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

The patent adds a vertical dimension to the resist system by introducing a resist underlayer film beneath the photoresist film. This dimensional expansion allows the photoresist film to be optimized for resolution (thin for fine patterns) while the underlayer compensates for the lost etching resistance, enabling miniaturization without sacrificing resolution performance

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If a pattern is formed with high aspect ratio, then fine patterning is achieved, but pattern collapse occurs due to excessive aspect ratio

Engineering Contradiction:
Improvefine patterning capabilityVSAvoidpattern stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

By segmenting the resist system into upper and lower layers with different functional optimizations, the patent enables the photoresist film to form fine patterns while the underlayer provides structural support and etching protection, preventing pattern collapse that would occur in a single thick-layer system

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The composition enables the formation of a resist underlayer film with superior etching resistance and planarizing capabilities, facilitating precise pattern transfer to substrates with complex structures, even at high temperatures and low oxygen concentrations, thus enhancing the accuracy of fine patterning in semiconductor manufacturing.

Implementation Method 1

a composition for forming a resist underlayer film, comprising: (A) a polymer having a structure represented by the following general formula (1A); (B) a crosslinking agent represented by the following general formula (B-1)

Methodology Applied
Scientific EffectCrosslinking: Chemical Bonding

Implementation Method 2

a resist underlayer film having a different etching selectivity from a photoresist film (i.e., a resist upper layer film) is placed between the resist upper layer film and a substrate to be processed

Methodology Applied
Scientific EffectDry etching resistance: Chemical Bonding

Data Source

PatentEP4400914B1Composition for forming resist underlayer film, patterning process, and method for forming resist underlayer film
Publication Date: 2025.12.17 SHIN ETSU CHEMICAL CO LTD
  • EP4400914B1 patent drawingFigure 1(A)~1(F)
  • EP4400914B1 patent drawingFigure 2(G)~3(K)
  • EP4400914B1 patent drawing

AI summary

The present invention is a composition for forming a resist underlayer film, containing: (A) a polymer having a structure represented by the following general formula (1A); (B) a crosslinking agent represented by the following general formula (B-1); and (C) an organic solvent, where the polymer (A) contains no hydroxy groups and the crosslinking agent (B) is contained in an amount of 5 to 50 parts by mass relative to 100 parts by mass of the polymer (A). This provides: a composition for forming a resist underlayer film that exhibits much better dry etching resistance than conventional resist underlayer film materials; a patterning process in which the composition is used as a resist underlayer film material; and a method for forming a resist underlayer film.